FYI: Group Policy Preferences > Regional Settings.

[pete]

If you've been wondering how to make that red underlining green:

 

F5: Mark all settings on the page as "green" (apply all)

F6: Mark current settings on the page as "green" (apply this settings)

F7: Mark current settings as "red" (don't apply this setting)

F8: Marks all settings on the page as "red" (don't apply)

 

F3: Gives a list of available variables.

 

Found here: Florian’s Blog » When I create a Regional Options Preference, my settings are not saved!